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XXL 



THE COlYCENTEATION AND PUEIFICATION OF ALCOHOLIC 

 FEEMEiNTTATION LIQUOES. 



Part I.— The Distillation in Steam of Certain Alcohols. 



By JOSEPH EEILLY, M.A., D.Sc, M.E.I.A., F.I.C., 



and 

 WILFEED J. HICKINBOTTOM, M.Sc, AJ.C. 



[Read January 25. I'ublished August 19, 1921.] 



The monohydric aliphatic alcoliols may be considered as being formed from 

 water by the substitution of an alkyl group for one of the hydrogen atoms. 

 They may also be regarded as hydroxyl derivatives of the saturated paraffins. 

 From the former standpoint the vi^ater-alcolrol mixtures w^ould be of the type 

 of closely -related liquids. According to the latter view, while paraffin- 

 alcohol mixtures would conform to this type, aqueous alcohol compositions 

 would more readily be classified among mixtures of not- closely-related liquids. 

 From both these aspects the subject has been studied by Young^ in his 

 investigation of the relationship of the alcohols to water on the one hand, 

 and to the paraffins on the other. In general the influence of the alkyl 

 group rapidly increases as we pass from methyl alcohol up the series. 

 Furthermore, from the study of the vapour pressures of various mixtures of 

 alcohols and water, ^ it has been shown that the relation between the mole- 

 cular percentage of methyl alcohol in the mixture and the corresponding 

 vapour pressure may be represented by an approximately straight line. 

 Comparisons were made by Young from Konowalow's data at such a 

 temperature that the vapour pressure of the pure alcohol in each case was 

 400 mm. "With the substitution of ethyl alcohol for methyl alcohol in the 

 above comparison, the relation is represented by a decided curve. In the 

 case of the higher alcohols the curve becomes still more pronounced. 



It would, therefore, appear that methyl alcohol water mixtures come into 

 the group of closely-related miscible liquids, while ethyl alcohol and water 

 mixture is better classified with the miscible Qwt-closely-related mixtures. 



I Trans. Chem, Soc, 1902, 81, 707. ^ Konowalow, Weld. Ann., 1881, 14, U. 



SCIBNT. PBGC. E.D.S., VOL. XVI, NO. XXI. 2 L 



